SEO means Search Engine Optimization. It's what you do to your website to make it easier for search engines to find you based on the keywords a person uses when they do a search.
There are going to be people who know they're looking for your company and will search by name. Usually your page will appear at the top of these search results. That's great, but it's not the only thing we're going for.
You want people who don't know about you to find you too. So, you need to make sure that your website uses key words that they would be looking for.
Just think about the things you would use to search for you. Maybe you are a yoga studio. A person would search yoga, yoga classes, yoga studio and the town they are in and probably the neighborhood. Maybe even the kind of yoga or things like kid-friendly or something else that would narrow it down.
If you want to check on where your listing would come up in a Google search, make sure you are signed out of Google or try on a different computer or browser (IE, Foxfire, Chrome) you haven't used (if you use Chrome, just open an incognito window). Google often shows you pages based on where you've been, so a simple search on your computer may not give you a true reading.